文件上传codeIgniter中的错误

Below is the code for my controller....

public function do_upload()
    {

        $config['upload_path']='./upload/';
        $config['allowed_types']='gif|jpg|png';
        $this->load->library('upload',$config);
        $this->upload->do_upload('image_file');
        if($this->upload->do_upload('image_file'))
        {
            $filedata = $this->upload->data();
            $filename = $filedata['raw_name'].$filedata['file_ext'];

            return $filename;
        }

    }

After this call this function where You want to make this upload...in controller

    if($_FILES)
                    {
                        $this->do_upload();
                    }

but file is not uploaded.......why?

Hope this will help you :

Your do_upload method should be like this :

public function do_upload() 
{
    $config['upload_path'] = './upload/';
    $config['allowed_types']='gif|jpg|png';
    $this->load->library('upload', $config);
    if($this->upload->do_upload('image_file'))
    {
        $filename = $this->upload->data('file_name');
        echo  $filename;die;
    }
    else
    {
        print_r($this->upload->display_errors());
        die;
    }
}

UPDATE :

set upload_max_filesize in your php ini greater than 2MB,

if it is wamp just follow :

click on wamp => php => php settings => upload_max_filesize

I think you missed this line.

$config['upload_path']='./upload/';

$config['allowed_types']='gif|jpg|png';

$this->upload->initialize($config);

$this->load->library('upload', $config);

if($this->upload->do_upload('image_file')) {

    $filename = $this->upload->data('file_name');
    echo  $filename;die;
}
else
{
    print_r($this->upload->display_errors());
    die;
}